Going deeper into the voids of Orion, longer exposure times combined with highly red-sensitive film reveal a delicate arc of nebulosity called "Barnard's Loop". The arc at the upper left seems to be quite faint, but the comparison to other objects like the Horsehead Nebula south of zeta Ori or the entirely overexposed Great Orion Nebula reveal the striking contrast between the thin gas filaments and "usual" astronomical showcase objects. The picture was made of two 45 minute exposures digitally stacked to overcome film granularity.
Barnard was an astronomer who is still well known for his catalog of dark nebulae.